Pileus Git - ~andy/linux/blob - arch/um/kernel/skas/process.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/sched.h"
   7 #include "linux/slab.h"
   8 #include "linux/ptrace.h"
   9 #include "linux/proc_fs.h"
  10 #include "linux/file.h"
  11 #include "linux/errno.h"
  12 #include "linux/init.h"
  13 #include "asm/uaccess.h"
  14 #include "asm/atomic.h"
  15 #include "kern_util.h"
  16 #include "as-layout.h"
  17 #include "skas.h"
  18 #include "os.h"
  19 #include "user_util.h"
  20 #include "tlb.h"
  21 #include "kern.h"
  22 #include "mode.h"
  23 #include "registers.h"
  24
  25 void switch_to_skas(void *prev, void *next)
  26 {
  27         struct task_struct *from, *to;
  28
  29         from = prev;
  30         to = next;
  31
  32         /* XXX need to check runqueues[cpu].idle */
  33         if(current->pid == 0)
  34                 switch_timers(0);
  35
  36         switch_threads(&from->thread.mode.skas.switch_buf,
  37                        &to->thread.mode.skas.switch_buf);
  38
  39         arch_switch_to_skas(current->thread.prev_sched, current);
  40
  41         if(current->pid == 0)
  42                 switch_timers(1);
  43 }
  44
  45 extern void schedule_tail(struct task_struct *prev);
  46
  47 /* This is called magically, by its address being stuffed in a jmp_buf
  48  * and being longjmp-d to.
  49  */
  50 void new_thread_handler(void)
  51 {
  52         int (*fn)(void *), n;
  53         void *arg;
  54
  55         if(current->thread.prev_sched != NULL)
  56                 schedule_tail(current->thread.prev_sched);
  57         current->thread.prev_sched = NULL;
  58
  59         fn = current->thread.request.u.thread.proc;
  60         arg = current->thread.request.u.thread.arg;
  61
  62         /* The return value is 1 if the kernel thread execs a process,
  63          * 0 if it just exits
  64          */
  65         n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
  66         if(n == 1){
  67                 /* Handle any immediate reschedules or signals */
  68                 interrupt_end();
  69                 userspace(&current->thread.regs.regs);
  70         }
  71         else do_exit(0);
  72 }
  73
  74 void release_thread_skas(struct task_struct *task)
  75 {
  76 }
  77
  78 /* Called magically, see new_thread_handler above */
  79 void fork_handler(void)
  80 {
  81         force_flush_all();
  82         if(current->thread.prev_sched == NULL)
  83                 panic("blech");
  84
  85         schedule_tail(current->thread.prev_sched);
  86
  87         /* XXX: if interrupt_end() calls schedule, this call to
  88          * arch_switch_to_skas isn't needed. We could want to apply this to
  89          * improve performance. -bb */
  90         arch_switch_to_skas(current->thread.prev_sched, current);
  91
  92         current->thread.prev_sched = NULL;
  93
  94 /* Handle any immediate reschedules or signals */
  95         interrupt_end();
  96
  97         userspace(&current->thread.regs.regs);
  98 }
  99
 100 int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 101                      unsigned long stack_top, struct task_struct * p,
 102                      struct pt_regs *regs)
 103 {
 104         void (*handler)(void);
 105
 106         if(current->thread.forking){
 107                 memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
 108                        sizeof(p->thread.regs.regs.skas));
 109                 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
 110                 if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
 111
 112                 handler = fork_handler;
 113
 114                 arch_copy_thread(&current->thread.arch, &p->thread.arch);
 115         }
 116         else {
 117                 init_thread_registers(&p->thread.regs.regs);
 118                 p->thread.request.u.thread = current->thread.request.u.thread;
 119                 handler = new_thread_handler;
 120         }
 121
 122         new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
 123                    handler);
 124         return(0);
 125 }
 126
 127 int new_mm(unsigned long stack)
 128 {
 129         int fd;
 130
 131         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 132         if(fd < 0)
 133                 return(fd);
 134
 135         if(skas_needs_stub)
 136                 map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 137
 138         return(fd);
 139 }
 140
 141 void init_idle_skas(void)
 142 {
 143         cpu_tasks[current_thread->cpu].pid = os_getpid();
 144         default_idle();
 145 }
 146
 147 extern void start_kernel(void);
 148
 149 static int start_kernel_proc(void *unused)
 150 {
 151         int pid;
 152
 153         block_signals();
 154         pid = os_getpid();
 155
 156         cpu_tasks[0].pid = pid;
 157         cpu_tasks[0].task = current;
 158 #ifdef CONFIG_SMP
 159         cpu_online_map = cpumask_of_cpu(0);
 160 #endif
 161         start_kernel();
 162         return(0);
 163 }
 164
 165 extern int userspace_pid[];
 166
 167 int start_uml_skas(void)
 168 {
 169         if(proc_mm)
 170                 userspace_pid[0] = start_userspace(0);
 171
 172         init_new_thread_signals();
 173
 174         init_task.thread.request.u.thread.proc = start_kernel_proc;
 175         init_task.thread.request.u.thread.arg = NULL;
 176         return(start_idle_thread(task_stack_page(&init_task),
 177                                  &init_task.thread.mode.skas.switch_buf));
 178 }
 179
 180 int external_pid_skas(struct task_struct *task)
 181 {
 182 #warning Need to look up userspace_pid by cpu
 183         return(userspace_pid[0]);
 184 }
 185
 186 int thread_pid_skas(struct task_struct *task)
 187 {
 188 #warning Need to look up userspace_pid by cpu
 189         return(userspace_pid[0]);
 190 }
 191
 192 void kill_off_processes_skas(void)
 193 {
 194         if(proc_mm)
 195 #warning need to loop over userspace_pids in kill_off_processes_skas
 196                 os_kill_ptraced_process(userspace_pid[0], 1);
 197         else {
 198                 struct task_struct *p;
 199                 int pid, me;
 200
 201                 me = os_getpid();
 202                 for_each_process(p){
 203                         if(p->mm == NULL)
 204                                 continue;
 205
 206                         pid = p->mm->context.skas.id.u.pid;
 207                         os_kill_ptraced_process(pid, 1);
 208                 }
 209         }
 210 }
 211
 212 unsigned long current_stub_stack(void)
 213 {
 214         if(current->mm == NULL)
 215                 return(0);
 216
 217         return(current->mm->context.skas.id.stack);
 218 }